Scientists have for the first time observed the phenomenon of three galaxies colliding, placing the supermassive black holes at their centers into a trajectory for merger.
The collision occurred nearly 1 billion light-years away from Earth, in the SDSS J084905.51+111447.2 star system. To observe this phenomenon, astronomers required both ground-based and space telescopes.
Researchers utilized the Sloan Digital Sky Survey Telescope in New Mexico to construct images of the star system by capturing light. The civil scholar community involved in the Galaxy Zoo project subsequently helped identify this star system as an intergalactic collision, according to CNN.
Many other research efforts were undertaken. Images captured by the Wide-field Infrared Survey Explorer (WISE) space telescope revealed infrared light emanating from the collision. The Chandra X-ray Observatory indicated several bright spots at the center of each galaxy.
The supermassive black holes in the trajectory of collision as three galaxies come together. (Photo: NASA).
NASA also employed NuSTAR, a space telescope designed to find X-rays in space using technology that focuses high-energy rays from nuclear spectral sources, to study this phenomenon. The survey results indicated that gas and dust were released from the collision.
Scientists connected these factors and discovered that massive black holes exist and are consuming material in the three galaxies. This rare collision study has been published in the Astrophysical Journal this week.
“Initially, we were just searching for black holes in the universe. However, through our selection system, we inadvertently encountered this fascinating star system,” said Pfeifle, a researcher at George Mason University.
“This is the most compelling evidence showing a triplet system with supermassive black holes that are ‘feeding’ and active,” Pfeifle added.
Despite the unimaginable scale of the collision, witnessing it is not easy. The black holes continuously consume material, causing the event to be obscured by dust and gas from human light-gathering instruments.
Scientists collected images and data across various spectral wavelengths to piece together the magnificent picture of the universe.
At the center of our Milky Way, there is also a supermassive black hole. The planet SO-2 is the closest and passed very near the center in 2018. (Photo: NASA).
While the phenomenon of two black holes nearing collision has been observed before, science has never recorded a “triple” collision involving galaxies and the supermassive black holes at their centers. Upon colliding, they will merge into an even larger black hole. The presence of three colliding black holes will accelerate the merger process.
Another consequence of this process will be gravitational waves, or fluctuations in the fabric of space and time.
“Double or triple black hole collisions are extremely rare. This is a natural consequence of galaxy mergers, which is also how they evolve and develop,” said Shobita Satyapal, a co-author of the study.
